1. Field of the Invention
This invention relates to gear reducing devices and more particularly, to a gear reducing device for application in sawmills and the like, which device is characterized by an input drive system and an output drive system located in a chamber or housing and separated by a rotating disc. The input drive system of the gear reducing device includes an input shaft having one end rotatably seated in axial alignment in one end of an output shaft and extending from the housing and driven by an electric motor and belt combination. A spur and pinion gear is secured to or shaped integrally with the input shaft and engages a pair of oppositely-disposed, larger input spur gears, each of which is provided with a fixed auxiliary spur gear, which input spur gears and auxiliary spur gears are rotatably mounted in spaced relationship on the disc. The auxiliary spur gears mesh with an output shaft spur gear that is keyed to the output shaft, which rotates independently of the input shaft, and, together with the input spur gears, drive the disc. The auxiliary spur gears are rotatably mounted along with the input spur gears, respectively, on a pair of auxiliary spur gear shafts which are press-fitted in spaced relationship along a diameter of the rotating disc, which is rotatably mounted on the output shaft. Accordingly, rotation of the input shaft at a selected speed effects planetary rotation of the input spur gears on the spur and pinion gear and the auxiliary spur gears on the output shaft spur gear. This rotation of the input spur gears around the spur and pinion gear also effects rotation of the disc on the output shaft in the opposite direction from the direction of rotation of the input shaft.
The output drive system of the gear reducing device includes an output spur gear keyed to the output shaft, a fixed gear spaced from the output shaft sprocket and mounted in fixed relationship to the housing and a pair of double spur gears rotatably mounted on the disc in spaced relationship and along a diameter in ninety degree disposed relationship with respect to the auxiliary spur gears, respectively. The fixed gear engages a common set of teeth in the double spur gears and the output spur gear engages an adjacent set of teeth in the double spur gears, respectively. Accordingly, rotation of the disc by operation of the input drive system effects rotation of the output spur gear and the output shaft, since the output spur gear is keyed to the output shaft. Rotation of the double spur gears drives the output shaft at a speed which is determined by the respective gear ratios of the spur and pinion gear, input spur gears, auxiliary spur gears, output shaft spur gear, output spur gear, fixed gear and double spur gears, respectively. The torque applied to the output shaft depends upon the relative number of teeth provided on the fixed gear and output spur gear, respectively, located in the output drive system.
2. Description of the Prior Art
Various devices are known in the art for achieving a mechanical advantage in gearing, power transmission, speed reduction and the like. Early U.S. Pat. No. 846,086, dated Mar. 5, 1907, to G. E. Bouvier, et al, entitled "Gearing", details a differential driving connection for decreasing the speed of bobbins in a fly-frame as the bobbins are filled and increased in diameter, in order to assure that the yarn on the bobbin will be wrapped with a desired degree of tension. U.S. Pat. No. 2,140,790, dated Dec. 20, 1938, to I.R. Davis, is entitled "Power Transmission". The power transmission mechanism is designed to develope maximum power using a pair of bevel gears coupled to a system of spur gears. U.S. Pat. No. 2,210,598, dated Aug. 6, 1940, to R. K. Pepper, et al, details a "Power Clutch Unit" adapted for use in connection with heavy duty, slow speed mechanisms such as Caterpillar tractors, power-operated shovels, trucks and the like. U.S. Pat. No. 2,312,908, dated Mar. 2, 1943, to F. R. Ibanez, details a "Mechanism for Transmitting Power" which includes chain-connected sprockets and meshing gears for speed reduction purposes. "Variable-Speed Gearing" is detailed in U.S. Pat. No. 2,582,620, dated Jan. 15, 1952, to G. Colucci. The device includes one pair of variable diameter pulleys driven by a V-belt or chain, where the tension is maintained in the chain or V-belt by the centrifugal force generated by rotation of the pulley system mounted on shafts carried by supports articulated to the axis of rotation of the pulley system. U.S. Pat. No. 2,653,490, dated Sept. 29, 1953, to E. Testori, details a "Progressive Variable Speed Drive Capable of Reverse Rotation". The system includes meshing gears and a V-belt and is designed to provide a progressive variable speed drive, by which it is possible to reach zero speed on the driven shaft while the driving shaft rotates at a selected speed. Reversal of the direction of rotation is also possible with the system. U.S. Pat. No. 3,130,608, dated Apr. 28, 1964, to L. H. Moran, details a "Chain-Type Speed Reducer" for transmitting power between rotatable members of the reducer and materially reducing the drive from a drive shaft to a driven shaft. The reducer employs a lever driven by the drive shaft for operating chains or the like circumferentially around a fixed sprocket to reduce the speed of the driven shaft. A "Variable Speed Power Transmission for Small Vehicles and the Like" is detailed in U.S. Pat. No. 4,048,871, dated Sept. 20, 1977, to N. G. Fyock. The transmission system includes primary and secondary transmissions connected in series, wherein a forward speed having a variable output depends upon the load placed on the input shaft to the primary transmission. The secondary transmission functions in one mode to reverse the direction of the output shaft, while the primary transmission operates to provide a variable gear ratio, depending upon the load placed upon the input shaft to the primary transmission. Other patents of interest are U.S. Pat. No. 2,122,330 dated June, 1938, to Stenzy; U.S. Pat. No. 4,044,633 dated August, 1977, to Lee; U.S. Pat. No. 3,979,971, dated September, 1976, to Generke, et al; U.S. Pat. No. 3,429,200, dated February, 1969, to Green; and U.S. Pat. No. 2,197,014, dated April, 1940, to Stenzy.
It is an object of this invention to provide a gear reducing device which utilizes an input shaft rotatably seated in one end of an output shaft, meshing input gears engaging the input shaft and output shaft on the input side of a rotating disc, and meshing output gears having a different number of teeth, connected to the output shaft on the opposite or output side of the disc, to create a mechanical advantage at the output shaft.
Another object of this invention is to provide a gear reducing device which utilizes an input shaft rotatably and linearly terminating in an output shaft coupled to a system of input gears located on the input side of a heavy disc or flywheel, to define an input drive system and output gears having a different number of teeth and located on the opposite side of the flywheel to define an output system, for driving the output shaft at a selected speed and torque.
Yet another object of this invention is to provide a gear reducing device which is characterized by an input drive mechanism having an input shaft carrying a spur and pinion gear that meshes with a pair of matching, oppositely-disposed input spur gears and auxiliary spur gears which are, in turn, rotatably attached to a rotating disc and mesh with an output shaft spur gear keyed to an output shaft rotatably receiving the input shaft in axial alignment. The output drive mechanism includes a pair of spaced double spur gears rotatably mounted on the disc and engaging an output spur gear having a first selected number of teeth and keyed to the output shaft and a fixed gear having a second selected number of teeth and secured to the housing of the gear reducing device, respectively, for creating low speed, high torque operation of the output shaft.
A still further object of this invention is to provide a new and improved gear reducing device which is characterized by a housing, all input shaft carrying a spur and pinion gear and journalled for rotation in one end of the housing and an output shaft journalled for rotation in the opposite end of the housing, one end of which input shaft is rotatably and axially seated in a corresponding end of the output shaft, and further including a disc or flywheel rotatably mounted on the output shaft and fitted with a pair of auxiliary spur gears for meshing with an output shaft spur gear keyed to the output shaft and a pair of input spur gears meshing with the spur and pinion gear, for driving the disc at a speed proportional to the speed of the input shaft. The disc is further provided with a pair of double spur gears engaging an output spur gear keyed to the output shaft and a fixed gear having a different number of teeth from the output spur gear and located on the output side of the disc, to determine the output shaft torque.